Not to pick on, but the 2009 model year marks a change in that Porsche fully did away with the IMS bearing. Although the IMS bearing was not completely abolished by the 2006-20008 (with the exception of a few very early model years that still had the leftover M96 engine), the failure of the bearing was essentially eradicated. I sincerely doubt that I have read about a single instance of an IMS failure on an M97 motor. It’s interesting to note that IMS bearings have been used in Porsche engines since the 996s. Every 911 from 1964 to 2008 had an IMS bearing, in actuality. Even the cherished Mezger automobiles, such as the Turbos and GT3s, lacked IMS bearings. They simply never fell short. The M96 motors’ failure was mostly the result of poor upkeep. It’s true that poorly designed seals permitted bearing failure in vehicles with little mileage and irregular oil changes. I have never saw an IMS bearing fail in a vehicle that was frequently driven and received regular/appropriate oil maintenance (at least once a year).
With Dwain Dement (the owner of Vision Motorsports), I had a lengthy conversation on the M97, M96, and 2009 direct injection motors. I even went on a tour of his engine manufacturing facility. Each year, Dwain produces around 100 M96 engines as well as almost as many M97 race motors. The IMS bearing is a genuinely trivial problem, which is funny. Any wear issues can be easily detected WELL before catastrophic failure with the right maintenance, etc. However, the majority of individuals simply follow the lore that is widespread online. The casting of the cylinders into the casing is the major problem with M96 motors that is frequently disregarded. They may crack with prolonged use or high mileage. Since their cases are thicker, M97 motors rarely experience cracking problems. According to Dwain, he has never witnessed an M97 motor’s IMS bearing fail. He claimed that the bearing is considerably bigger and stronger.
The M97 IMS failure rate is interestingly close to zero…even with rather subpar care. Additionally, due to how much larger the bearing is than its predecessor, it cannot be replaced until the engine case is opened. Since they are better for higher RPM and a little more durable than direct injection motors in terms of boring to bigger displacement, etc., Dwain employs the M97 motor for the majority of his race car engines. After each race, he conducts an oil study on every M97 engine he supports (well over 20-cars). It’s interesting to note that he rarely observes excessive metal wear until there has been a serious missed shift, which he notes using the Motec(r) system, which is far more accurate than the original DME.
Sorry for the rant, but I’ve written numerous articles about it, visited four engine shops, and spoken with a ton of mechanics and engine builders, including Dwain, Deiter (Andial), Tony Callas, and others. There are numerous misconceptions regarding IMS bearings, etc. I went directly to folks who see these motors and bearings on a daily basis rather than depending on what is written online or in magazines.
Personally, I believe that direct injection motors are given far too much credit. Think about all the troubles that VW and BMW are experiencing with that configuration. All day long, I would choose an M97 engine to save money.
In This Article...
How to Determine If Your Porsche IMS Bearing Is at Risk for Failure
From 1999 until 2006, the IMS bearing for these engines underwent numerous design improvements, including both single-row and dual-row bearing designs, but the problem was never sufficiently fixed. The “9A1” engine, the first 911-bound engine to totally do away with the intermediate shaft arrangement in favor of a technology that powers the camshafts straight off the crankshaft, eventually supplanted the M96 and M97 engines. That’s fantastic news if you purchased a 911 from the 2009 model year or later that has the more modern 9A1 engine, but what can you do to avoid IMS bearing failure if you buy a 911 with an M96 or M97 engine? How can you avoid being the victim of a failing IMS bearing if you’re trying to purchase a used 911?
Does the 996 911 suffer from the Porsche IMS bearing?
Furthermore, according to Rennlist and Pelican Parts forum users, owners of 996 Turbo, GT2 or GT3 models are exempt from Porsche IMS bearing problems. The so-called “Mezger engine” was indeed utilized in these, but it had a modified design that fixed the IMS fault.
The later 997’s IMS problems were also resolved by switching to the Mezger engine, which bears the name of one of Porsche’s illustrious engineers, Hans Mezger. According to Revolution Porsche Specialists, the earlier (2005–2008) 997.1 vehicles still had IMS bearing problems. The company asserts that Porsche 911s manufactured between 2000 and 2005 are the ones that experience IMS bearing failures the most commonly. However, a new engine design for the 2009 997.2 Porsche 911 eliminated the problematic IMS bearing. Any Porsche 911 made in 2009 or after is therefore protected from IMS bearing failure.
Fortunately, even though the IMS problem had an impact on resale values, Porsche 911 sales weren’t greatly harmed. A 996 or 997.1 911 can be an incredibly economical entry into Porsche ownership as long as you keep that in mind.
How to Avoid an IMS Bearing Problem
The 9A1 engine, which employs engineering that drives the camshafts directly from the crankshaft instead of using the IMS system, replaced the M96 and M97 engines after 2009. If you own one of these years and models, this is fantastic news for you. However, if you own one of the earlier models, you can upgrade the IMS with a bearing retrofit to prevent failure. The possibility of the IMS bearing failing is eliminated by the design, components, and serviceability of an upgrade.
Which Porsche models are susceptible to IMS bearing failure?
All Boxster, Cayman, and 911 vehicles from MY1997 to MY2008, with the exception of Turbo, GT2, and GT3 variants, are susceptible to IMS bearing failure.
But over time, the types of bearings utilized changed, and some of them were more likely to fail than others. According to statistics, the Boxster 986 and 911 models built between model years 2000 and 2005 are the most likely to experience IMS bearing failure, whereas the odds are extremely low for a Boxster 987 or Cayman built after a stronger bearing was introduced in late 2005.
In terms of mileage, there is no clear trend in the failures; some owners were unfortunate enough to encounter IMS issues at less than 20,000 miles, while others assumed they were safe only to have the bearing fail at 130,000 miles. In summary, you should be aware of potential issues if you now own or intend to purchase one of the versions with the weaker bearing that were in use from 2000 until late 2005.
The base engine (3.6) bears the designation “M96,” and depending on your engine number, you may have the smaller IMS or the revised bigger bearing:
Engine (3.6) number M96/05 69507476 has the larger updated IMS bearing, while Engine (3.6) number M96/05 69507475 has the smaller IMS bearing.
The “S” Engine (3.8) is designated “M97” and features a choice of a smaller or bigger upgraded IMS bearing:
Engine (3.8) numbers beginning with M97/01 68509791 have the larger updated IMS bearing, whereas Engine (3.8) numbers up to M97/01 68509790 have the previous IMS bearing.
How much does a Porsche 911’s IMS bearing cost to replace?
Thousands of independent technicians advocate IMS Retrofit ceramic hybrid ball bearing as the best preventive treatment because it is the only long-term fix for IMS bearing issues in M96/M97 engines. IMS Retrofit replacement bearings typically cost more than $4,000 in labor and materials, but they can be installed at the same time as the clutch. Compared to the price of rebuilding or replacing the entire engine, this is a relatively low expenditure. The cost of this repair should be weighed against the minimal likelihood that an IMS breakdown will occur in an older Porsche. You might decide it is worth the risk if you carefully evaluate the possibility of a future failure and compare it to the cost of an IMS Retrofit bearing. This preventative procedure, however, may very well be a worthwhile outlay to avoid future harm and larger spending in the future if you are worried about the health and well-being of your Porsche.
Which year Porsches experience IMS issues?
The intermediate shaft bearing, commonly known as an IMS bearing, has a significant failure rate in the Porsche 911 and Porsche Boxster from model years 1997 to 2005. Its build and design cause the bearing to prematurely fail, which causes a catastrophic engine failure.
How long is the life of IMS bearing?
Failure of an IMS bearing can occur at any time. While some bearings only last for 3,000 miles, others can survive for 200,000 miles or more. Failure happens randomly and regardless of mileage.
IMS bearing failure can occur for a variety of causes, including multiple ones. However, it appears that the IMS bearings shipped from the factory have two significant weaknesses:
- The ball bearing’s construction material isn’t robust enough to endure both the thermal and physical demands.
- The bearings are not adequately lubricated.
Some engine failures are caused by the back IMS bearing failing to seal, which then enables the grease to be washed off by contaminated engine oil. When open ball or roller bearings without seals are in use, any pollution in the engine oil might cause the bearing to wear out more quickly. This results in the failure of the IMS bearing.